Slingshot is nothing new; Facebook launched it back in the summer as place where users can share images of real events as they happen. However, since the launch, there has been a bit of feedback from users and Facebook have taken notice, so this is the new Slingshot and it has some interesting new features to play with. Originally, the idea was that you sent an image to your friends and they were only able to view it by sending an image back, it is a fair swap. Now Slingshot works a bit more like apps such as Snapchat, you can follow friends and share an image that goes into a feed, then viewers can see the image by posting an image of their own.
The images will stick around for either 24 hours or until they are viewed, but users are able to skip through images and comment on them as they view. Slingshot is a much better app now, it offers more features and functions than before, and it also has the advantage of being linked to Facebook. This app is free and available from Google Play for Android devices and iTunes for iOS devices.
Source: Sling Blog